Abstract: A mixer for preparing silver halide grains for photographic use has upper and lower impellers housed in a draft tube. The bottom impeller has flat blades for micromixing silver and halide reactants introduced into the bottom of the draft tube. The upper impeller has pitched blades for macromixing the bulk fluid. The impellers are spaced apart at least the distance of their diameters so that the upper and lower impellers operate independently of one another so that micromixing is independent of macromixing. A flow disrupter structurally associated with the draft tube and positioned above the top impeller prevents vortexing of the fluid during mixing. Baffles may be provided in the draft tube to discourage vortexing.

Abstract: A process for the preparation of a radiation-sensitive silver halide emulsion comprised of high chloride cubical silver halide grains containing from 0.05 to 3 mole percent iodide, based on total silver, where the iodide is incorporated in the grains in a controlled, non-uniform distribution forming a core containing at least 50 percent of total silver, an iodide free surface shell having a thickness of greater than 50 Å, and a sub-surface shell that contains a maximum iodide concentration is disclosed, the process comprising: (a) providing in a stirred reaction vessel a dispersing medium and host high chloride silver halide cubical grains comprising a speed enhancing amount of iodide, and (b) precipitating silver halide onto the host grains by introducing at least a silver salt solution into the dispersing medium at a rate such that the normalized molar addition rate, Rn, is above 3.

Abstract: A dimethylamine silver chloride complex is used as a single source precursor for nucleation of silver chloride crystals.

Abstract: The invention generally relates to a method of silver halide grain finishing comprising providing a high chloride silver halide grain emulsion and adding a silver bromide fine grain Lippmann emulsion during the chemical sensitization heat cycle for each grain wherein said fine grain emulsion has a photographically useful compound adhered to said fine grain Lippmann emulsion.